Semiconductor device

Abstract

In one embodiment, an IGBT is formed to include a plurality of termination trenches in a termination region of the IGBT. An embodiment may include that one end of one or more termination trenches may be exposed on one surface of the semiconductor device.

The invention claimed is: 
     
       1. An IGBT comprising:
 a semiconductor substrate having a first surface and a second surface that is disposed opposite to the first surface; 
 a first doped region of a first conductivity type overlying the first surface wherein a first P-N junction is formed along the first doped region; 
 a second doped region of the first conductivity type on the second surface of the semiconductor substrate and extending a first distance into the semiconductor substrate; 
 a third doped region having a second conductivity type in the second doped region and extending a second distance into the second doped region; 
 a plurality of termination trenches in a termination region of the semiconductor device, the plurality of termination trenches surrounding an outer perimeter of the second doped region and extending from the second surface toward the first surface wherein at least a portion of an end of one or more termination trenches of the plurality of termination trenches extends through the first surface; and 
 a plurality of gate structures extending through the third doped region and into the second doped region. 
 
     
     
       2. The IGBT of  claim 1  wherein an end of each termination trench of the plurality of termination trenches extends through the first surface. 
     
     
       3. The IGBT of  claim 1  wherein a first termination trench of the plurality of termination trenches has an insulator along sidewalls, along a first end, and along a second end of the first termination trench with a space interior to the first termination trench with the space positioned between the insulator that is along sidewalls, along the first end, and along the second end of the first termination trench. 
     
     
       4. The IGBT of  claim 3  wherein the space is one of evacuated, or a vacuum, or partial vacuum, or filled with a gas. 
     
     
       5. The IGBT of  claim 1  wherein one or more termination trenches of the plurality of termination trenches has an insulator along sidewalls, along a first end, and along a second end of the one or more termination trenches with a space positioned between the insulator that is along sidewalls, along the first end, and along the second end of the one or more termination trenches. 
     
     
       6. The IGBT of  claim 1  wherein one or more termination trenches of the plurality of termination trenches has an insulator along sidewalls, along a first end, and along a second end of the one or more termination trenches with a conductor positioned interior to the one or more termination trenches with the conductor positioned between the insulator that is along sidewalls, along the first end, and along the second end of the one or more termination trenches. 
     
     
       7. The IGBT of  claim 6  wherein the conductor is doped polysilicon. 
     
     
       8. An IGBT comprising:
 a semiconductor substrate having a first surface and a second surface that is disposed opposite to the first surface; 
 a first doped region of a first conductivity type overlying the first surface wherein a first P-N junction is formed along the first doped region; 
 a second doped region of the first conductivity type on the second surface of the semiconductor substrate and extending a first distance into the semiconductor substrate; 
 a third doped region having a second conductivity type in the second doped region and extending a second distance into the second doped region wherein an interface between the second and third doped regions forms a second P-N junction and an interface between the second doped region and a portion of the semiconductor substrate forms a third P-N junction; and 
 a plurality of termination trenches in a termination region of the semiconductor device, the plurality of termination trenches surrounding an outer perimeter of the second doped region and extending from the second surface toward the first surface wherein at least a portion of an end of one or more termination trenches of the plurality of termination trenches extends through the first surface and wherein at least one termination trench of the plurality of termination trenches abuts distal ends of the first, second and third P-N junctions. 
 
     
     
       9. A semiconductor device comprising:
 a semiconductor material of a first conductivity type having a first surface and a second surface that is disposed opposite to the first surface; 
 a first doped region of a second conductivity type on the first surface; 
 a second doped region of the second conductivity type on the second surface of the semiconductor material and extending a first distance into the semiconductor material; 
 a third doped region having the first conductivity type, the third doped region positioned in the second doped region and extending a second distance into the second doped region; and 
 a plurality of termination trenches in a termination region of the semiconductor device, the plurality of termination trenches surrounding an outer periphery of the first doped region and extending from the second surface toward the first surface wherein at least a portion of at least one termination trench of the plurality of termination trenches abuts the outer periphery of the first doped region and an outer periphery of the second doped region. 
 
     
     
       10. The semiconductor device of  claim 9  wherein a first P-N junction is formed along the first doped region and wherein the at least one termination trench abuts distal ends of the first P-N junction wherein the distal ends are substantially adjacent to the outer periphery of the first doped region. 
     
     
       11. The semiconductor device of  claim 10  wherein the second doped region forms a second P-N junction with the semiconductor material and the at least one termination trench abuts distal ends of the second P-N junction wherein the distal ends are at substantially the outer periphery of the second doped region. 
     
     
       12. The semiconductor device of  claim 9  wherein each termination trench of the plurality of termination trenches include an insulator material and wherein the insulator material of each termination trench of the plurality of termination trenches abut each other so that substantially no doped semiconductor material is disposed between any of the plurality of termination trenches. 
     
     
       13. The semiconductor device of  claim 9  wherein an outer periphery of the plurality of termination trenches forms an outer periphery of a die on which the semiconductor device is disposed and wherein the outer periphery of the plurality of termination trenches is substantially devoid of doped semiconductor material. 
     
     
       14. The semiconductor device of  claim 9  wherein the at least one termination trench also abuts the third doped region along an outer periphery of the third doped region.